37. The expert from France, Chair of the Frontal Impact IWG, introduced the latest draft amendments of his group (ECE/TRANS/WP.29/GRSP/2014/23) to the draft UN Regulation (ECE/TRANS/WP.29/GRSP/2014/10) on frontal impact with focus on the restraint system, with a thorax compression criterion (ThCC) of 42 mm. He also introduced GRSP-56-36, showing three possible solutions to implement a ThCC of 34 mm for the Hybrid III fifth percentile female dummy as requested by the expert from Japan. The expert from OICA introduced GRSP-56-13-Rev.1 endorsing 42 mm criterion because more balanced to protect both young and elderly people. He added that if a decision would be taken by GRSP to endorse 34 mm, this should be introduced at a later stage as a new series of amendments. The expert from Japan introduced GRSP-56-23-Rev.2 aimed at supporting a ThCC of 34 mm and stated that this value was evidence based for its feasibility. The expert from Sweden stated that she was not in the position to support one of the two values. The expert from Italy was in favour of 42 mm because the ThCC of 34 mm criterion needed further investigation. The expert from EU announced that a test programme (sponsored by the European Union) would start at the beginning of 2015 to investigate on this issue. GRSP agreed to resume discussion at its May 2015 session on the basis of revised proposals to be submitted by the expert from France (including GRSP-56-13-Rev.1 and GRSP-56-23-Rev.2).

37. The expert from France, Chair of the FI IWG, introduced the status report of the group (GRSP-55-43) as well as the latest amendments (GRSP-55-20-Rev.1) to the official proposal (ECE/TRANS/WP.29/GRSP/2014/10) of a new UN Regulation on frontal impact with focus on the restraint system. He added that the IWG focused on two possible scenarios for the threshold of front passenger’s thorax compression criteria:
(a) thorax compression criteria (Thcc) of ≤ 34 mm (considering the injury risk curve for the elderly 5th percentile female);
(b) Thcc ≤ 42 mm (considering the injury risk curve for the 5th percentile female).

38. He asked GRSP for guidance on choosing the scenario to be addressed by the draft UN Regulation. The expert from EC suggested that the first scenario complemented by an additional test (e.g. sled test) with a 95th percentile male dummy. However, the expert from France reminded GRSP that the proposal aimed to reduce the number of tests. The expert from OICA presented a recommendation (GRSP-55-42) for a Thcc ≤ 42 mm to address the 5th percentile female because a Thcc of ≤ 34 mm would only address a limited percentage of the population and because the test tool variations need to be taken into account. He remarked that the higher injury risk for elderly occupants would be considered by a reduced Thcc threshold of 42 mm for the 50th percentile male dummy Hybrid III as was also proposed for UN Regulation No. 94. GRSP finally agreed to resume consideration of this agenda item at its December 2014 session and requested its experts to provide clear guidance on the two above-mentioned scenarios. The secretariat was requested to distribute GRSP-55-20-Rev.1 with an official symbol at the next session of GRSP.